Fuel injection pump



Nov. 19, 1957 w. o. BISCHOFF 2,813,523 FUEL INJECTION uMP Filed Oct. 29. 1953 2 Sheets-Sheet 2 INVENTOR. WA LDE MAE 0.1515010 A T OENEY.

States Patent Ofiice 2,813,523 Patented Nov. 19, 1957 FUEL INJECTION PUMP Waldemar O. Bischoff, Holyoke, Mass., assignor to American Bosch Arma Corporation, a corporation of New York Application October 29, 1953, Serial No. 388,974 4 Claims. or. 123-439 This invention relates to fuel injection apparatus and has particular reference to a new and improved injection timing arrangement for distributor type fuel injection pumps which employs a combined pumping and distributing member.

An object of the invention is to provide a new and improved apparatus of the type set forth which is relatively simple and less expensive to manufacture and assemble and trouble free in operation.

Another object is to provide an apparatus of, the type set forth which is of the high pressure metering type and which has relatively simple and inexpensive timing means.

Another object is to provide an apparatus of the type set forth wherein the metering means may be adjusted for controlling the timing of injection.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will be understood that changes may be made in the details of construction and arrangement of parts without departing from the spirit of the invention, as set forth in the accompanying claims.

Referring to the drawings:

Fig. 1 is a sectional view taken on line 11 of Fig. 3, looking in the direction of the arrows;

Fig. 2 is a fragmentary sectional view of the device shown in Fig. 1, but on an enlarged scale;

Fig. 3 is a longitudinal sectional view of the apparatus embodying the invention; and

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2, looking in the direction of the arrows.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout, the device shown embodying the invention comprises the pump head which fits into a recess in the main pump housing 11 and is secured thereto by bolts or the like, not shown.

The cam shaft 12 is mounted for rotation in said housing 11 on the ball bearing 13 and bearing 14 respectively, and mounting flange 15 is provided for securing the pump assembly in position on the engine. On the cam shaft 12 is provided the helical gear 16 which is rotated upon rotation of the cam shaft 12 and which meshes with a gear shaft, not shown, driving gear 18 on plunger 19 and thereby rotating plunger 19 as described in Patent 2,518,473 to which reference is made for further description and operation.

The hydraulic head 10 has outlets 20, one of which is provided for each combustion chamber adapted to receive fuel from the device, and which outlets are connected to their respective combustion chambers by pipe lines 21.

The hydraulic head 10 has an inlet port 22 adapted to be connected by a hydraulic line, not shown, to the fuel supply pump or other source of fuel and is connected through the port 23 to the pumping chamber 24. The hydraulic head 10 also has the outlet or return port 25 adapted to be connected by a hydraulic line to the fuel tank and in said line may be positioned a check valve for controlling or maintaining the desired fuel supply pressure in the pump.

The spill chamber 26 is connected by the passage 27 and 28 to the ports 25 and 22 respectively. Port 25 is connected by port 29 with pumping chamber 24.

Plunger 19 is adapted to be reciprocated by cam 30 on cam shaft 12 upon the rotation of the cam shaft.

The plunger 19 is provided with the axial hole or passage 31 which communicates with pumping chamber 24 through ports 32 and 33 with slots 34 and 35 respectively on the periphery of plunger 19. It will be noted that slot 35 extends in a straight direction whereas slot 34 is helically positioned, that is, it extends in a helical direction relative to slot 35. Sleeve 36 surrounds plunger 19 and overlies both slots 34 and 35 and is provided with the bypass or spill ports 37, one of which is provided for each outlet 20.

It will be noted that sleeve 36 may be adjusted axially, relative to plunger 19, by means of shaft 33 and eccentric connection 39 in peripheral slot 42 in sleeve 36 whereby the quantity of fuel bypassed may be controlled, thereby controlling the quantity of fuel injected. The timing of injection is controlled through shaft 40 with eccentric connection 41 in slot 43 and adapted to rotate sleeve 36 relative to plunger 19.

Peripheral slot 42 allows rotary motion of the sleeve without disturbing the axial position and axial slot 43 allows vertical adjustment of the sleeve without disturbing the rotary adjustment thereof.

It will be noted that the timing of beginning and ending of injection can be controlled depending upon the direc tion of rotation of sleeve 36 whereby the injection may be advanced or retarded in relation to the drive.

It will be noted that the injection stroke may have various characteristics through the selection of the shape and relative positions of the grooves in the plunger. By having one slot parallel to the axis of the plunger and the other angled it is possible to have a constant beginning and variable ending to the injection stroke, or a variable beginning and constant ending, dependent upon the direction of rotation. Both variable beginning and variable ending in one stroke can be achieved by angling both slots in relation to the axis of the plunger. From the foregoing it will be seen that one of the ports controls the beginning of injection and the other controls the end of injection.

In Patent 2,518,473 there is disclosed an arrangement for varying the timing of injection of apparatus of the type set forth and which requires separate sleeves and axially displaced ports in the plunger, whereas in the present invention, only one sleeve is employed with a pair of grooves and ports in the plunger with means for rotating the sleeve and the present arrangement provides a simple, economical and fool proof arrangement whereby the timing of injection may be easily and quickly varied at will.

From the foregoing it will be seen that I have provided simple, efiicient and economical means for obtaining all of the objects and advantages of the invention.

I claim:

1. In a device of the character described, a combined pumping and distributing plunger member, means for reciprocating said plunger member for pumping fuel and for rotating said plunger member for distributing fuel, said plunger member having longitudinal bore means and a pair of circumferentially spaced ports communicating with said bore means, one of said ports controlling the beginning of injection and the other controlling the end of injection, a pair of slots in said plunger, each of said slots communicating with one of said spaced ports, and

a sleeve surrounding said plunger member and overlying said ports, said sleeve having port means adapted to communicate with said port means in said plunger member and means for pivoting said sleeve about saidplunger member.

2. In a device of the character described, a combined pumping and distributing plunger member, means for reciprocating said plunger member forv pumping fuel and for rotating said plunger member for distributing fuel, said plunger member having longitudinal bore means and a pair of circumferentially spaced ports communicating with said bore means, one of said ports controlling the beginning of injection and the other controlling. the end of injection, a pair of slots in saidplunger, each of. said slots communicating with one of said spaced ports, and a sleeve surrounding said plunger member and overlying said ports, said sleeve having port means adapted to communicate with said port means in said plunger member and means for pivoting said sleeve about said plunger member, and meansfor moving said sleeve axialof said plunger member.

3. In a device of the character described, abore, a

plunger mounted for reciprocating and rotating in said.

bore for pumping and distributing fuel to-a plurality. of outlets successively, said plunger having an axial bore and a pair of spaced ports communicating with said bore, one

of said ports controlling the beginning of injection and theother controlling the end of injection, a pair of slots in a pair of 'circumferentially spaced ports communicating with said bore, one of said ports controlling the beginning of injection and the other controlling the end of injection, a pair of slots in said plunger, each of said slots communicating with one of said spaced ports, said slots being in angled relation, a sleeve'overlying saidports, said sleeve having port means, means for moving said sleeve axial of said plunger and means for pivoting said sleeve relative to said plunger.

References Cited in the file of this patent UNITED STATES PATENTS 2,544,561 Meyer Mar. 6, 1951 2,624,327 Hogeman Jan. 6, 1953 2,657,631 Evans Nov. 3, 1953 FOREIGN PATENTS 442,475 Great Britain Feb. 10, 1936 

